Migration of organic compounds from PET/clay nanocomposites: influences of clay type, content and dispersion state

Abstract

Polyethylene terephthalate (PET) bottles are widely used for packaging mineral water or soft drinks. Migration of toxic residual phthalate esters from PET could potentially change the quality of the bottled contents. The main purpose of this study is to control the migration of five different phthalate esters from PET bottles into the water they contained. To achieve this goal, three different types of nanoclay particles were added to PET to slow down the migration of the toxic phthalate esters. The concentration of phthalate esters in the water in contact with PET and PET/nanoclay was measured by gas chromatography (GC-FID) combined with the directly suspended droplet microextraction method. Good precision, accuracy and reproducibility over a wide linear range were achieved by the proposed technique under optimal conditions. The experimental results reveal that adding nanoclay fillers to the PET decreases the release of the above-mentioned chemicals from PET into the water considerably due to attainment of a tortuous diffusive path. Data also indicate the significant effect of nanoclay volume fraction and exfoliated morphology on obtaining efficient barrier properties. Furthermore the effects of parameters such as storage time, temperature, and amount and type of nanoclay inclusions were studied on the migration rate, as well.